ESE's works engine tuner

[TZ350]

Why ......... with the best power main jet fitted. On straight Methanol this thing would run on after a full throttle 10,000 RPM dyno pull. With the petrol meth combination it still runs on after a big dyno pull.
I would expect that enriching it up would be the cure but interestingly the richer I made the methanol main jet the worse the running on became. Why?????.......

Two thoughts, one the Methanol float chamber runs low during a pull (4,3 Delorto Methanol float seat) or there is so much combustion-able fuel being blown through into the pipe mixing with air drawn back through the stinger that its feeding the engine through the exhaust port. Could that be possible? I know that at closed throttle the average pressure in the crank case and exhaust chamber are near atmospheric. So atmospheric air does flow back into the system through the stinger.

When I can I will ask someone to observe the fuel level during a pull to see what happens. Any other suggestions of what to look for would be very welcome.

[F5 Dave]

Is ignition ignitech?
Or are you running a wasted spark ignition? Hmm, single engine, so not likely. . ,

No. No idea

[Grumph]

Very basic question. What plug are you running ?

[husaberg]

Questions i would ask.
Is the main jet really big enough?
is the needle jet too small and acting as a defacto main jet?
Is the fuel flow adequate..

[F5 Dave]

Questions i would ask.
Is the main jet really big enough?
is the needle jet too small and acting as a defacto main jet?
Is the fuel flow adequate..

Ooh. 3. Takes us back to probably my first post near page 1 I guess

[husaberg]

Ooh. 3. Takes us back to probably my first post near page 1 I guess

Yes i was thinking this also, although i thought it was rob talking about his imported tuner (Thomas)

okay you both said it.
First place i remember seeing it was in Bells book

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This is Thomas a Vietnamese race mechanic, you know that place where they have all those hot 50's and 125's are big bikes.

Thomas, ESE's Race Team's Tuner is fettling number 9. adjusting the port timing for Taupo.

Its hard to see but he has taped a degree wheel to the magneto flywheel so he can mark out the exhaust port height he wants.

None of this raise the port 3.5mm for a gazillion HP nonsense. He knows what timing he needs and sets the crank position there before marking the port and then doing the hells death port job that we all dream of.

You should see him setting up a carb. Talk about pain staking, he starts with a main jet so big the bike floods at about half throttle (apparently this proves the oriface of the needle/needle jet combo is big enough) and then he slowly step by step works back until it runs clean.

Most people start at the bottom with a carb and work up, He starts at the top and works backwards.

Never seen him blow one up. But then he is intelligent with the throttle and does not ring its neck when the engine is in distress.

Boy o Boy am I Looking forward to Taupo.

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Just add another nut to the end of flywheel, then you can add a bolt that secures the degree wheel. Pointer must be secure (I use a clamped on scriber) & degree wheel should be as big as possible. Barrel must be bolted down well or gives incorrect readings, this can be a problem if engine has thru bolts & a few gaskets used. Use feeler gauge to determine if port is closed by piston, doing it by eye is imprecise.

When starting with another carb just pull the mainjet out, no point putting a big one in. If the engine doesn’t bog past ½ way then the needle is too fat.

[speedpro]

It may seem irrelevant and in this case it may be, but a long time ago in Wellington I was trying to get a crankcase reed RGV/TS combo to run. I'd set the timing to more or less what I knew worked on previous engines. The problem was that it would not rev out properly. Looking down the wide open carb when it was having it's little hissy fit I could see flames dancing around down by the reed valves. In the end out of total frustration I advanced the timing way past where I'd ever had it previously and the damn thing ran sweet. If all else fails give it a go I reckon.

Some sort of valve on the end of the pipe to close it off might be a good idea until the issue is resolved.

[F5 Dave]

And your piston didn't close the bridged ex port if I remember.

[Flettner]

I dont know, but with ethanol you do need to up your fueling when the engine gets hot, or else this very thing happens. Clearly EFI is the go for this but in your class its not legal I guess. Are you running a surface fire plug? Mazda rotary have B11 heat range, surface fire, although a bit expensive.

[TZ350]

Is ignition ignitech? Or are you running a wasted spark ignition? Hmm, single engine, so not likely. . , No. No idea

Yes, good thought. It is a twin Ignitech but with both channels firing into a single coil. Wasted spark?, could be I suppose if the channels are firing 180 apart. I will have to take another look at the settings.

[TZ350]

Very basic question. What plug are you running ?

I have tried several different kinds. Surface gap, and very cold 10's and 11's NGK's and cold Champion competition plugs with fine wire electrodes. Maybe platinum acts as a catalyst for Methanol???? must check that.

[TZ350]

Questions i would ask. Is the main jet really big enough? is the needle jet too small and acting as a defacto main jet? Is the fuel flow adequate..

Good questions, I will have to check them carefully. Definitely big question mark over number three.

The Methanol float bowl has a 4,3 Methanol needle seat and the hoses are fairly large internal diameter. But best by test, so I will see if I can get someone to observe the fuel level during a run.

[TZ350]

I dont know, but with ethanol you do need to up your fueling when the engine gets hot, or else this very thing happens. Clearly EFI is the go for this but in your class its not legal I guess. Are you running a surface fire plug? Mazda rotary have B11 heat range, surface fire, although a bit expensive.

Under plug head temperature hits 105 deg C when making best power but runs on. Bigger jet, and the head temp only hit 85 deg C but runs on much worse.

EFI is specifically banned for Pre 72. Otherwise EFI would have been my choice.

[Flettner]

Yes, good thought. It is a twin Ignitech but with both channels firing into a single coil. Wasted spark?, could be I suppose if the channels are firing 180 apart. I will have to take another look at the settings.

I had that issue, run it with just one channel firing, see whar happens. Although with me it didnt run on, it just ran crap. On petrol.

[TZ350]

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Here we go:- "Fire and Flame" with Platinum and Methanol https://youtu.be/A2VpA_301rg?si=4JvV0KvNTtNQ8OMD not the total answer for me as not all the plugs I tried had Platinum electrodes.